textproduct: Rapid City

KEY MESSAGES

- Cooler temps expected through Thursday

- Rain through midweek to bring beneficial moisture

- Hot and dry weather returns next weekend

UPDATE

Issued at 948 PM MDT Mon Jul 20 2026

Slight cooldown and a brief break from the heat expected to commence tomorrow through late in the week as upper level ridging weakens. With highs dropping into the 80s for the next several days, have let the heat advisory expire. Additional heat headlines may be needed over the weekend as upper level ridge strengthens once more and temperatures progged to reach into the triple digits once more.

As the ridge breaks down, we'll see increasing chances for rain/storms by the mid-week. Still looking at PWAT values of 175- 200% over the area by Wednesday/Thursday as a series of waves move over the region. Much of the area could see wetting rainfall with localized amounts of over an inch.

DISCUSSION

(This Evening Through Monday) Issued at 220 PM MDT Mon Jul 20 2026

Strong ridging persists across the western CONUS with upper flow over the CWA becoming increasingly northwesterly. Surface obs show the cold front across SCentral SD, with showers near the boundary. These showers will continue SE and exit the area this afternoon. Current temps are generally in the upper 80s to mid 90s. Smoke in the area has hindered temps from getting as warm as expected...and likewise, apparent temps. Will leave the Heat Advisory out but could see it being cancelled before 03z. Temps on Tuesday through Thursday will be a cool 80s each day. After a dry day on Tuesday, a wave pushing through is expected to bring showers and isolated thunderstorms overnight into Wednesday morning. Most models keep QPF on the light side, but the ECM/RRFS/NAM show some locations getting well over half an inch. This will be possible with PWATs of 150-175% of normal. The next series of waves will approach as the upper ridge weakens. These slow-moving waves are expected to bring showers and thunderstorms to the area late Wednesday into Thursday. The latest run of the GFS shows an impressive 175-200% of normal, which could bring localized QPF amounts of over an inch. Hot weather with +100F temps could return for the weekend as the ridge sets up again across the western CONUS.

AVIATION

(For the 12Z TAFS Through 12Z Wednesday Morning) Issued At 518 AM MDT Tue Jul 21 2026

VFR conditions will prevail through 22/00z. After 22/00z, some showers/thunderstorms will move across the region with local IFR conditions. Have mentioned thunder at the KGCC site this evening, but only mentioned showers at KRAP after 22/06z for now.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.